Investigation of the process of microrelief structures formation in chromium films based on the method of chemical etching

• Date: 2021
• Main Authors: Панкратова, А. В., Крючин, А. А., Бородін, Ю. О., Беляк, Є. В., Пригун, О. В.
• Format: Article
• Language: Ukrainian
• Published: Інститут проблем реєстрації інформації НАН України 2021
• Subjects: microrelief structure; chemical etching; laser recording; sapphire substrates; mathematical modeling; chromium film; photoresist layer
• Online Access: http://drsp.ipri.kiev.ua/article/view/235022
• Journal Title: Data Recording, Storage & Processing

Modern approaches used in the formation of microrelief structures on the surface of highly stable single-crystal substrates are considered. The priority of submicron photolithography methods, in particular, the use of plasma chemical etching with a multilayer mask is shown. The analysis of the technological process of applying a protective mask based on chromium in the formation of the information layer of the optical disk with a sapphire substrate is carried out. Thermochemical technology of direct resistive laser recording is considered. It is shown that thermochemical technology in comparison with photoresist technology is characterized by a smaller number of technological operations and a smaller range of laser beam power. It is supposed that the main technological problem of microrelief structure forming on the surface of a monocrystalline sapphire substrate by chemical and plasma chemical-etching is the accumulation of electric charge on the surface of the sapphire substrate, which prevents the formation of a microrelief structure. To eliminate the effect of accumulation of electric charge on the surface of the sapphire substrate, it was proposed to use a two-layer mask based on a layer of photoresist and metal film. Mathematical modeling of the normalized intensity distribution as a function of the thickness of the chromium layer at the standard thickness of the photoresist layer made it possible to determine the suitability of the material and to form requirements for choosing the optimal thickness of the metal film. The results of mathematical modeling indicated a decrease of the illumination rate up to the decrease of the chromium film thickness. An experimental study of the micro-dimensional elements formation in thin chromium films was also performed. As a result of experimental research, the conditions for optimizing the process of laser recording in the medium of the photoresist mask used in the chemical etching of the chromium film during the formation of the microrelief structure on the surface of the sapphire substrate were determined. Tabl.: 1. Fig.: 8. Refs: 11 titles.